Cancer is suspected based on a person's symptoms, the results of a physical examination, and sometimes the results of screening tests. Occasionally, x-rays obtained for other reasons, such as an injury, show abnormalities that might be cancer. Confirmation that cancer is present requires other tests (termed diagnostic tests). After cancer is diagnosed, it is staged. Staging is a way of describing how advanced the cancer has become, including such criteria as how big it is and whether it has spread to neighboring tissues or more distantly to lymph nodes or other organs.